Yards per carry is one of the most commonly referenced statistics when measuring a running back’s efficiency on the ground. Despite its popularity, and despite using it quite often myself, I loathe the statistic. It’s inherently biased, favoring running backs with good offensive lines, running backs who see a high percentage of carries against poor run defenses, running backs who see a high percentage of carries on likely passing downs, or running backs who might be inconsistent but compile a high percentage of their yardage on relatively few carries. Like all statistics, it’s one that’s much better served when looking at it with more context, and that’s what I’m hoping to do here today.

Pro Football Focus helped revolutionize how we look at running back efficiency by creating the “elusive rating” metric. This statistic helps “distill the impact of a runner independently of the blocking in front of him by looking at how difficult he was to tackle.” The focus here is on yards after contact per attempt and missed tackles forced per attempt, rather than raw yardage totals. You can access these numbers yourself here if you’re a PFF Elite subscriber. I’ve already discussed the league leaders by these statistics in depth in a few other articles this offseason. So, instead, I’ll break down yards per carry a few other less-traditional methods with a focus on fantasy implications.

First, we’re going to look at all running backs with at least 100 carries last season, and how frequently their carries went for “x-or-more yards.” In this space last year, we (accurately) identified Isaiah Crowell as a potential regression candidate, considering a whopping 37 percent of his total rushing yardage in 2016 came on just five percent of his carries.

Kenyan Drake was other-worldly last season, by a number of different metrics, and I wrote about his historically impressive 2017 season here. Still, one concern is the small sample size (just six starts), but an additional concern is that he averaged a 20-plus-yard run on 5.3 percent of his carries, which ranks 18th-best among all running backs to see at least 100 carries in a single season this past decade. Only 24 times within our sample (Bilal Powell’s 2017 is one of them) did a running back average a 20-plus-yard run on over five percent of his carries. This may seem like a positive, but it’s actually a tad worrisome for me.

In the PFF era (2007-2017) there have been 22 instances of a running back totaling at least 100 carries and averaging a 20-plus-yard run on over five percent of their carries, and also drawing at least 100 carries in the subsequent season. On average, these running backs averaged a 20-plus-yard run on 6.16 percent of their carries in the first season, but that number fell to just 2.83 percent in the following year. For perspective, the league average rate is 2.55 percent.

Basically, this is not a very sticky or predictive metric, and it’s likely Drake may have just gotten lucky, and that this number is likely to fall in 2018. The same thing is true for running backs to post an especially low rate of 20-plus-yard runs. 37 running backs in our sample averaged a 20-plus-yard run on less than one percent of their carries. On average, these running backs averaged a 20-plus-yard run on 0.6 percent of their carries, but in the following season that number climbed to 2.30 percent. So, for running backs at either extreme of this metric, their numbers are likely to stabilize closer to the league-average rate in 2018. That’s not encouraging for Drake, but it should be for someone like Le’Veon Bell (0.9 percent).

Leonard Fournette’s numbers are also a concern, for similar reasons. He didn’t post a high rate of 20-plus-yard runs, but these runs did make up a significant percentage of his total yardage. Just two of his carries (0.7 percent of his total carries) make up 15.9 percent of his total rushing yardage. I got on my soapbox midway through the season and started ranting about a looming regression, after I felt fantasy owners were paying too high of a price for what I felt amounted to just two fluky 75-plus-yard runs. It turns out, I was right. If we strip out his two longest runs of the season, he falls from 18th-worst (3.88), to second-worst (3.29) in yards per carry — the largest drop among all qualifying running backs. As evident also by his below-average ranking in about all of the above statistics, Fournette’s 2017 was highly underwhelming, but his fantasy value was buoyed by two long runs, volume, and touchdowns.

Of the above statistics, five-plus percent actually had the highest correlation year-over-year (0.17) to yards per carry in the following season (among running backs with at least 100 carries in back-to-back years). Alvin Kamara led the league in this category, followed by Dion Lewis, Todd Gurley, and then Wayne Gallman. Gallman was one of the names who surprised me most in this chart, and his numbers here (also that he was rarely tackled for zero or negative yardage) are encouraging for his 2018 fantasy prospects so long as New York doesn’t try to replace him in the draft.

In our next chart, we’re going to look at all 2017 running backs to total at least 75 carries on a single team and contrast their yards per carry average to that of their running back teammates.

Green Bay’s Aaron Jones stands out in the best way possible. Earlier this offseason, ESPN’s Matthew Berry, per his sources, said (paraphrased) all three Green Bay running backs will be involved, but Jones is the running back you’ll want to own by midseason. That sounds about right to me. Jones dominated on the ground, but did struggle in pass protection, surrendering a near-league-worst five pressures on 31 pass-blocking snaps. Perhaps that is the only thing left in the way of him taking over as the team’s primary early-down back.

Similarly, Kareem Hunt dominated here, but was even worse than Jones as pass-blocker. If he can improve in that department, his relative efficiency should render Charcandrick West obsolete. Though, of course, now we do have to worry about the return of Spencer Ware. Still, I’m confident Hunt is the far superior talent, head coach Andy Reid has rarely employed a committee throughout his career, and recent offseason comments actually point towards a larger role for Hunt in 2018.

It’s interesting to note how much better Giovani Bernard appears relative to rookie Joe Mixon. Cincinnati had our fifth-worst offensive line last year, but even relative to blocking Mixon struggled, ranking bottom-six (of 53 qualifying running backs) in yards after contact per attempt and missed tackles forced per attempt. Cincinnati has indicated a desire to make Mixon their bell cow, but he’ll need to be far more efficient than he was last season to keep that role.

Drake ran circles around the Miami iteration of Jay Ajayi. While the Philadelphia version of Ajayi looks much better by this metric, Miami’s running game fared far better with Drake in place of Ajayi.

Mike Gillislee really seemed to earn his role on the bench last season, ranking as one of our least efficient running backs relative to his peers. Needless to say, I’m not optimistic regarding his 2018 prospects, and especially after the team added Jeremy Hill in the offseason to (presumably) compete for goal-line work alongside Gillislee and Rex Burkhead.

Again, Fournette looks extremely underwhelming here, averaging 3.88 yards per carry to his teammates’ 4.53. The Jaguars placed a second-round tender on Corey Grant (worth $2.9 million) this offseason and I don’t think that’s insignificant. Grant averaged 8.3 yards per carry last season, after averaging 5.1 the year before. It’s a small 62 carry sample, but it seems he does deserve to eat into Fournette’s carries next year. T.J. Yeldon also averaged an impressive 5.2 yards per carry on 49 attempts last season. I’ve been lower on Fournette than most since he was drafted, but he should retain RB1-status so long as the volume and scoring opportunities are there. Though Fournette may need to play better if he wants to keep his workhorse role.

In our next chart, we’re looking at expected yards per carry versus a running back’s actual yards per carry. Expected yards per carry is calculated based on a defense’s average yards per carry allowed and is weighted by a running back’s carries against each defense.

Alvin Kamara posted the fourth-best yards per carry season since the NFL merger (1970), so of course he’s going to rank highly in this chart and all other charts. His ranking here wasn’t a surprise for me, but Todd Gurley’s certainly was. As amazing as he was last season, he looks far better when taking strength of schedule into account, sporting the third-lowest expected yards per carry average of all 47 rushers with at least 100 carries. Last season, 33 percent of Gurley’s carries came against defenses ranking top-six in yards per carry allowed.

If you’re curious why Denver chose to release C.J. Anderson, perhaps this chart can posit an explanation. Anderson appeared above average in raw yards-per-carry average (4.11), but relative to a 4.18 yards-per-carry expectation (fifth-highest in our sample), he was well below average.

Ameer Abdullah had the toughest strength of schedule (lowest expected yards per carry average), but still performed well below his expectation. Mixon had the second-toughest strength of schedule (Bernard’s season ranked 16th-toughest), but also performed below his expectation.

To add another concern for Drake’s 2018 outlook, he actually had the easiest strength of schedule (highest expected yards-per-carry average) among all 100-plus-carry rushers last season. This could also be a concern for Hunt (fourth-easiest), though both look impressive enough relative to their schedules.

It’s worth noting that Jerick McKinnon ranked well below-average here and in all other charts. Although San Francisco was an ideal landing spot and receiving production makes up a large percentage of his fantasy value, I do feel we’re overlooking the fact that he’s been a below-average runner throughout his career. Prior to 2017, he never significantly out-snapped Matt Asiata and his 3.5 career yards-per-carry average. He’s a player that, although I’m high on, I worry his buzz is rising higher than my projection for him – especially in non-PPR leagues.

Notes: Earlier this offseason, I also looked at yards per carry relative to blocking advantage. You can read that article here. (Spoilers: Leonard Fournette and Jerick McKinnon again looked underwhelming.)